IS http://www.crystalgraphics.com/ Is a agence of BIGstock?
I found my file there and there is bigstock's watermark on it.

Back in the day, (1990's, I think,) Crystalgraphics sold 3d rendering programs. One such program, Crystal 3D,
running in MS DOS, had many advanced features, such as setting the position
of lighting in a scene to the sun's coordinates, and others. For it's time it was nicely
done software.